Snow storms often leave behind reminders of their presence for days - sometimes weeks - after warmer and sunnier weather returns. Snowbanks, often created by snow plows as they clear major roadways, can linger in parking lots, on sidewalks, and in driveways even when temperatures rise well above freezing.

Biomedical engineers are growing tracheas by coaxing cells to form three distinct tissue types after assembling them into a tube structure-without relying on scaffolding strategies currently being investigated by other groups.